I've found they have been getting a bit harder to come by recently, quite often there are 8 min waits. But provided I don't travel in the peak I can usually get a car pretty quickly. I always use Comfort wherever I can and I use Uber several times every day without any problems at all. All trips now have the PIN and I like the fact that it's super safe, I know who is going to take me, I know I've got the right car as they have the PIN, and I like that they charge my credit card and I don't have to route around to find cash to pay.